Typically some tanks in a wet process system contain chemicals for treating wafers carried by a wafer cassette while some tanks contain deionized (DI) water for rinsing wafers. The chemical containing tanks generally clean, etch or strip elements from wafers carried by the cassettes when the cassettes are lowered into the chemical bath. The DI water rinse tanks are typically used to rinse off the chemical residue after the wafers have been cleaned, etched or stripped.